We report techniques and results of a Palomar 200-inch ( 5 m ) adaptive optics imaging survey of sub-stellar companions to solar-type stars .
The survey consists of K _ { s } coronagraphic observations of 21 FGK dwarfs out to 20 pc ( median distance \sim 17 pc ) .
At 1″separation ( 17 projected AU ) from a typical target system , the survey achieves median sensitivities 7 mag fainter than the parent star .
In terms of companion mass , that corresponds to sensitivities of 50 M _ { J } ( 1 Gyr ) , 70 M _ { J } ( solar age ) , and 75 M _ { J } ( 10 Gyr ) , using the evolutionary models of Baraffe and colleagues .
Using common proper motion to distinguish companions from field stars , we find that no system shows positive evidence of a previously unknown substellar companion ( searchable separation \sim 20-250 projected AU at the median target distance ) .